module 4 Flashcards
Desication
loss of water to the enivorment
water balance
difference in water concentration between the organism and its environments
hydration
replacing water that has been lost to the air
Wip (plants internal water)
war+wa-wt-ws (r-roots-a-air-t-transpirtation-w-secrections)
waxy cuticle
Covering the above ground parts of plant; prevents gas exchange
Wia
Wd + Wf + Wa - We - Ws (+ Wm) Wia= Animal's internal water Wd = DrinkingWf = Food Wa = Absorbed from air We = Evaporation Ws = Secretion / Excretion Wm = Metabolic Water
Effect of gravity
in water vs. terestrial organisms
in water
buyouncay helps
terrestrial organisms must make their own support
how animals protect themselves
internal skeletons, external skeletons
how fungi protect themselves
cell wall of chitin
how plants protect themselves
cell walls of cellulose
terrestrial environments are highly variable
through both time and space
Variable both daily and seasonally
temperature variation, percipitation variation
these fluctuations (variations in temp and precipitation) have
short term effects on metabolic processes
long term effects on distribution and evolution of organisms.
Plant Distributions
Climate
ecological tolerance
Ecological Tolerances
Plants Have Ranges of Existence
light in forest vs. grassland
forest top has more light
grassland bottom has more light
foliage density
exposed as leaf area
leaf area-measured on one or both sides
leaf area index
LAI as you move from the top of the tree canopy to the ground?
area of leaves per unit ground areaLAI as you move from the top of the tree canopy to the ground?
-leaf area decreases as height decreases
leaf orientation
affects the change in light quality (attenuation) through the canopy
Leaf perpendicular to the sun
absorbs 1.0 unit of light energy per leaf unit area/time
Leaf at a 60∞ angle to the sun
absorbs 0.5 unit of light energy
Leaves at an ______ absorb light more effectively
angle
angles of leaves vary because of
angle of the sun varies
soil
Solid substrate of terrestrial communities resulting from the interaction of weather and biological activities with the underlying geological formation
soil is
the medium for plant growth
the initial recipient of water, controlling its fate
a recycling system
a habitat
base
Regolith
base is hard, unweathered rock
Layer of unconsolidated debris from crumbled rock that overlays this base
Soil is composed of
Minerals from Parent Rock
Organic Material
Water
Mechanical weathering results from the interaction of
water, temp, wind, organisms
mechanical weathering
Does not change them chemically
Chemical weathering
Chemically transforms the original rocks and minerals
examples of chemical weathering
soil organisms, decomposition organic material
five interrelated factors of soil formation
parent material biotic factors climate topography time
Soil Formation: Parent material
Material from which soil develops
Physical character & chemical composition important in determining soil properties
Can originate from: underlying bedrock glacial deposits (till) windborne sand/silt (eolian) gravity moving material down slope (colluvium) sediments carried by flowing water (fluvial)
colluvium
gravity moving material down a slope
fluvial
sediments carried by flowing water
geological events in soil create
mosaic under soil, diversity of soil
role of plants in soil formation
transfer light energy to the soil as organic carbon root, break up parent material, reduce erosion, bring nutrients to surface, stabilize soil surface
animals role in soil formation
burrow and dig into the soil
funi ang bacteria role in soil formation
Decompose remains of organisms, increasing organic material
soil formation
climate
Influences soil development directly and indirectly
soil formation abiotic factors
Influence Physical & Chemical reactions
Influence Physical & Chemical reactions
Temperature Controls the rate of biochemical reactions
Precipitation Water required for chemical weathering and leaching
Winds
weathering, leaching and plant growth are maximized under what conditions and have much less influence under what conditions
maximized under warm temperatures and abundant water
much less influence under cold, dry conditions
Topography can affect the influence of
climate
steep slopes will have
water runoff surface, soil is drier, erosion
not steep slope, top of mountain
thinner soil, soil not much nutrients
Soil Formation: Time
Important in soil formation,All of the factors discussed work over long periods of time,Formation of well-developed soil may take 2000 to 20,000 years.
Soils are distinguished by physical and chemical properties, including:
color texture structure moisture depth
Dark soil
Indicate Organic matter
Blotchy soil (yellow-brown/gray)
water saturated soils
Grasslands type of soil
Deep soils - grasses have deep roots, add organic material to soil
forest type of soil
-what is the source of organic material
shallow soils-falling leaves are major source of organic material
forest type of soil
Shallow soils - falling leaves are major source of organic material
soil classifications based on
can see
microscopic
based on proportions
can see-sand, silt, microscopic-clay
clay controls the most important properties:
cater-holding capacity
exchange of ions between particles and solution
Ideal soil
50% soil particles, 50% pore space
coarse soils have
Large pore spaces
Rapid water infiltration, percolation, drainage
As texture becomes finer
pores are smaller
More surface area for water adhesion & chemical activity
Very fine soils
easily compacted, smaller pore spaces, poor aeration, difficult for root penetration
matric potential
increases when
The energy associated with attractive forces on the surfaces of large molecules inside cells or on the surfaces of soil particles.Increases As Water Leaves soil
field capacity
lower in what soils
higher in what soils
Water held within the soil by internal capillary forces
Varies with texture
lower in coarse soils; higher in fine soils
wilting point
Moisture level at which plants cannot extract water
available water capacity
field capacity - wilting point
gravitational water
water that trickles downward through soil to ground water
O horizon
Organic Layer of freshly fallen organic material
Most superficial layer
A horizon
Mixture of minerals, clay, silt and sand
B horizon
Clay, humus, & other materials leached from A horizon
Often contains plant roots
C horizon
weathered parent material
Leaching
movement of nutrients and mineral down Into soil
higher H+ concentration ______ in leaching
increases
LAI as you move from the top of the tree canopy to the ground?
cumulative leaf area and LAI decreases
light decreases
slopes are deeper where and shallow where
deeper in valleys shallow on ridges
